1. Technical Field
The present disclosure relates to an electrosurgical system and method and, more particularly, to duty cycle controlled waveforms and modulated waveforms for use in optimizing tissue separation.
2. Background of Related Art
Energy-based tissue treatment is well known in the art. Various types of energy (e.g., electrical, ohmic, resistive, ultrasonic, microwave, cryogenic, laser, etc.) are applied to tissue to achieve a desired result. Electrosurgery involves application of high radio frequency electrical current to a surgical site to cut, ablate, coagulate or seal tissue. In monopolar electrosurgery, a source or active electrode delivers radio frequency energy from the electrosurgical generator to the tissue and a return electrode carries the current back to the generator. In bipolar electrosurgery, one of the electrodes of the hand-held instrument functions as the active electrode and the other as the return electrode. The return electrode is placed in close proximity to the active electrode such that an electrical circuit is formed between the two electrodes (e.g., electrosurgical forceps). In this manner, the applied electrical current is limited to the body tissue positioned between the electrodes.
During the cutting process, the generator supplies an electrical signal at a fixed sinusoidal frequency to an electrosurgical instrument to cut the tissue. Occasionally, the tissue will not completely separate and become completely desiccated because the tissue dries or loses moisture as the electrical signal is applied to the tissue. The desiccated tissue has a very high electrical impedance. An object of the invention is to provide modulated or duty cycle controlled waveforms with higher voltages to completely separate the tissue while keeping the root mean square (RMS) power low.